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<pre><span class="sourceLineNo">001</span><a name="line.1"></a>
<span class="sourceLineNo">002</span>/*<a name="line.2"></a>
<span class="sourceLineNo">003</span> * Copyright (C) 2014 Archie L. Cobbs. All rights reserved.<a name="line.3"></a>
<span class="sourceLineNo">004</span> *<a name="line.4"></a>
<span class="sourceLineNo">005</span> * $Id: BerkeleyKVTransaction.CursorIterator.html 939 2015-05-29 01:16:17Z archie.cobbs $<a name="line.5"></a>
<span class="sourceLineNo">006</span> */<a name="line.6"></a>
<span class="sourceLineNo">007</span><a name="line.7"></a>
<span class="sourceLineNo">008</span>package org.jsimpledb.kv.bdb;<a name="line.8"></a>
<span class="sourceLineNo">009</span><a name="line.9"></a>
<span class="sourceLineNo">010</span>import com.sleepycat.je.Cursor;<a name="line.10"></a>
<span class="sourceLineNo">011</span>import com.sleepycat.je.CursorConfig;<a name="line.11"></a>
<span class="sourceLineNo">012</span>import com.sleepycat.je.DatabaseEntry;<a name="line.12"></a>
<span class="sourceLineNo">013</span>import com.sleepycat.je.DatabaseException;<a name="line.13"></a>
<span class="sourceLineNo">014</span>import com.sleepycat.je.LockConflictException;<a name="line.14"></a>
<span class="sourceLineNo">015</span>import com.sleepycat.je.OperationStatus;<a name="line.15"></a>
<span class="sourceLineNo">016</span>import com.sleepycat.je.Transaction;<a name="line.16"></a>
<span class="sourceLineNo">017</span><a name="line.17"></a>
<span class="sourceLineNo">018</span>import java.io.Closeable;<a name="line.18"></a>
<span class="sourceLineNo">019</span>import java.util.Iterator;<a name="line.19"></a>
<span class="sourceLineNo">020</span>import java.util.NoSuchElementException;<a name="line.20"></a>
<span class="sourceLineNo">021</span>import java.util.concurrent.TimeUnit;<a name="line.21"></a>
<span class="sourceLineNo">022</span><a name="line.22"></a>
<span class="sourceLineNo">023</span>import org.jsimpledb.kv.AbstractKVStore;<a name="line.23"></a>
<span class="sourceLineNo">024</span>import org.jsimpledb.kv.KVPair;<a name="line.24"></a>
<span class="sourceLineNo">025</span>import org.jsimpledb.kv.KVTransaction;<a name="line.25"></a>
<span class="sourceLineNo">026</span>import org.jsimpledb.kv.KVTransactionException;<a name="line.26"></a>
<span class="sourceLineNo">027</span>import org.jsimpledb.kv.RetryTransactionException;<a name="line.27"></a>
<span class="sourceLineNo">028</span>import org.jsimpledb.kv.StaleTransactionException;<a name="line.28"></a>
<span class="sourceLineNo">029</span>import org.jsimpledb.util.ByteUtil;<a name="line.29"></a>
<span class="sourceLineNo">030</span>import org.jsimpledb.util.CloseableTracker;<a name="line.30"></a>
<span class="sourceLineNo">031</span>import org.slf4j.Logger;<a name="line.31"></a>
<span class="sourceLineNo">032</span>import org.slf4j.LoggerFactory;<a name="line.32"></a>
<span class="sourceLineNo">033</span><a name="line.33"></a>
<span class="sourceLineNo">034</span>/**<a name="line.34"></a>
<span class="sourceLineNo">035</span> * Oracle Berkeley DB Java Edition {@link KVTransaction} implementation.<a name="line.35"></a>
<span class="sourceLineNo">036</span> */<a name="line.36"></a>
<span class="sourceLineNo">037</span>public class BerkeleyKVTransaction extends AbstractKVStore implements KVTransaction, Closeable {<a name="line.37"></a>
<span class="sourceLineNo">038</span><a name="line.38"></a>
<span class="sourceLineNo">039</span>// Note: locking order: (1) BerkeleyKVTransaction, (2) BerkeleyKVDatabase<a name="line.39"></a>
<span class="sourceLineNo">040</span><a name="line.40"></a>
<span class="sourceLineNo">041</span>    private static final byte[] MIN_KEY = ByteUtil.EMPTY;                   // minimum possible key (inclusive)<a name="line.41"></a>
<span class="sourceLineNo">042</span>    private static final byte[] MAX_KEY = new byte[] { (byte)0xff };        // maximum possible key (exclusive)<a name="line.42"></a>
<span class="sourceLineNo">043</span><a name="line.43"></a>
<span class="sourceLineNo">044</span>    private final Logger log = LoggerFactory.getLogger(this.getClass());<a name="line.44"></a>
<span class="sourceLineNo">045</span>    private final BerkeleyKVDatabase store;<a name="line.45"></a>
<span class="sourceLineNo">046</span>    private final Transaction tx;<a name="line.46"></a>
<span class="sourceLineNo">047</span>    private final CursorConfig cursorConfig = new CursorConfig().setNonSticky(true);<a name="line.47"></a>
<span class="sourceLineNo">048</span>    private final CloseableTracker cursorTracker = new CloseableTracker();  // unclosed Cursors are tracked here<a name="line.48"></a>
<span class="sourceLineNo">049</span><a name="line.49"></a>
<span class="sourceLineNo">050</span>    private boolean closed;<a name="line.50"></a>
<span class="sourceLineNo">051</span><a name="line.51"></a>
<span class="sourceLineNo">052</span>    /**<a name="line.52"></a>
<span class="sourceLineNo">053</span>     * Constructor.<a name="line.53"></a>
<span class="sourceLineNo">054</span>     */<a name="line.54"></a>
<span class="sourceLineNo">055</span>    BerkeleyKVTransaction(BerkeleyKVDatabase store, Transaction tx) {<a name="line.55"></a>
<span class="sourceLineNo">056</span>        assert store != null;<a name="line.56"></a>
<span class="sourceLineNo">057</span>        assert tx != null;<a name="line.57"></a>
<span class="sourceLineNo">058</span>        this.store = store;<a name="line.58"></a>
<span class="sourceLineNo">059</span>        this.tx = tx;<a name="line.59"></a>
<span class="sourceLineNo">060</span>    }<a name="line.60"></a>
<span class="sourceLineNo">061</span><a name="line.61"></a>
<span class="sourceLineNo">062</span>// KVTransaction<a name="line.62"></a>
<span class="sourceLineNo">063</span><a name="line.63"></a>
<span class="sourceLineNo">064</span>    @Override<a name="line.64"></a>
<span class="sourceLineNo">065</span>    public BerkeleyKVDatabase getKVDatabase() {<a name="line.65"></a>
<span class="sourceLineNo">066</span>        return this.store;<a name="line.66"></a>
<span class="sourceLineNo">067</span>    }<a name="line.67"></a>
<span class="sourceLineNo">068</span><a name="line.68"></a>
<span class="sourceLineNo">069</span>    /**<a name="line.69"></a>
<span class="sourceLineNo">070</span>     * Get the underlying {@link Transaction} associated with this instance.<a name="line.70"></a>
<span class="sourceLineNo">071</span>     *<a name="line.71"></a>
<span class="sourceLineNo">072</span>     * @return the associated transaction<a name="line.72"></a>
<span class="sourceLineNo">073</span>     */<a name="line.73"></a>
<span class="sourceLineNo">074</span>    public Transaction getTransaction() {<a name="line.74"></a>
<span class="sourceLineNo">075</span>        return this.tx;<a name="line.75"></a>
<span class="sourceLineNo">076</span>    }<a name="line.76"></a>
<span class="sourceLineNo">077</span><a name="line.77"></a>
<span class="sourceLineNo">078</span>    @Override<a name="line.78"></a>
<span class="sourceLineNo">079</span>    public void setTimeout(long timeout) {<a name="line.79"></a>
<span class="sourceLineNo">080</span>        if (timeout &lt; 0)<a name="line.80"></a>
<span class="sourceLineNo">081</span>            throw new IllegalArgumentException("timeout &lt; 0");<a name="line.81"></a>
<span class="sourceLineNo">082</span>        this.tx.setLockTimeout(timeout, TimeUnit.MILLISECONDS);<a name="line.82"></a>
<span class="sourceLineNo">083</span>    }<a name="line.83"></a>
<span class="sourceLineNo">084</span><a name="line.84"></a>
<span class="sourceLineNo">085</span>// KVStore<a name="line.85"></a>
<span class="sourceLineNo">086</span><a name="line.86"></a>
<span class="sourceLineNo">087</span>    @Override<a name="line.87"></a>
<span class="sourceLineNo">088</span>    public synchronized byte[] get(byte[] key) {<a name="line.88"></a>
<span class="sourceLineNo">089</span>        if (this.closed)<a name="line.89"></a>
<span class="sourceLineNo">090</span>            throw new StaleTransactionException(this);<a name="line.90"></a>
<span class="sourceLineNo">091</span>        this.cursorTracker.poll();<a name="line.91"></a>
<span class="sourceLineNo">092</span>        if (key.length &gt; 0 &amp;&amp; key[0] == (byte)0xff)<a name="line.92"></a>
<span class="sourceLineNo">093</span>            throw new IllegalArgumentException("key starts with 0xff");<a name="line.93"></a>
<span class="sourceLineNo">094</span>        final DatabaseEntry value = new DatabaseEntry();<a name="line.94"></a>
<span class="sourceLineNo">095</span>        try {<a name="line.95"></a>
<span class="sourceLineNo">096</span>            final OperationStatus status = this.store.getDatabase().get(this.tx, new DatabaseEntry(key), value, null);<a name="line.96"></a>
<span class="sourceLineNo">097</span>            switch (status) {<a name="line.97"></a>
<span class="sourceLineNo">098</span>            case SUCCESS:<a name="line.98"></a>
<span class="sourceLineNo">099</span>                return value.getData();<a name="line.99"></a>
<span class="sourceLineNo">100</span>            case NOTFOUND:<a name="line.100"></a>
<span class="sourceLineNo">101</span>                return null;<a name="line.101"></a>
<span class="sourceLineNo">102</span>            default:<a name="line.102"></a>
<span class="sourceLineNo">103</span>                throw this.weirdStatus(status, "get");<a name="line.103"></a>
<span class="sourceLineNo">104</span>            }<a name="line.104"></a>
<span class="sourceLineNo">105</span>        } catch (DatabaseException e) {<a name="line.105"></a>
<span class="sourceLineNo">106</span>            throw this.wrapException(e);<a name="line.106"></a>
<span class="sourceLineNo">107</span>        }<a name="line.107"></a>
<span class="sourceLineNo">108</span>    }<a name="line.108"></a>
<span class="sourceLineNo">109</span><a name="line.109"></a>
<span class="sourceLineNo">110</span>    @Override<a name="line.110"></a>
<span class="sourceLineNo">111</span>    public KVPair getAtLeast(byte[] minKey) {<a name="line.111"></a>
<span class="sourceLineNo">112</span>        try (CursorIterator i = this.getRange(minKey, null, false)) {<a name="line.112"></a>
<span class="sourceLineNo">113</span>            return i.hasNext() ? i.next() : null;<a name="line.113"></a>
<span class="sourceLineNo">114</span>        }<a name="line.114"></a>
<span class="sourceLineNo">115</span>    }<a name="line.115"></a>
<span class="sourceLineNo">116</span><a name="line.116"></a>
<span class="sourceLineNo">117</span>    @Override<a name="line.117"></a>
<span class="sourceLineNo">118</span>    public KVPair getAtMost(byte[] maxKey) {<a name="line.118"></a>
<span class="sourceLineNo">119</span>        try (CursorIterator i = this.getRange(null, maxKey, true)) {<a name="line.119"></a>
<span class="sourceLineNo">120</span>            return i.hasNext() ? i.next() : null;<a name="line.120"></a>
<span class="sourceLineNo">121</span>        }<a name="line.121"></a>
<span class="sourceLineNo">122</span>    }<a name="line.122"></a>
<span class="sourceLineNo">123</span><a name="line.123"></a>
<span class="sourceLineNo">124</span>    @Override<a name="line.124"></a>
<span class="sourceLineNo">125</span>    public synchronized CursorIterator getRange(byte[] minKey, byte[] maxKey, boolean reverse) {<a name="line.125"></a>
<span class="sourceLineNo">126</span>        if (this.closed)<a name="line.126"></a>
<span class="sourceLineNo">127</span>            throw new StaleTransactionException(this);<a name="line.127"></a>
<span class="sourceLineNo">128</span>        this.cursorTracker.poll();<a name="line.128"></a>
<span class="sourceLineNo">129</span>        final Cursor cursor;<a name="line.129"></a>
<span class="sourceLineNo">130</span>        try {<a name="line.130"></a>
<span class="sourceLineNo">131</span>            cursor = this.store.getDatabase().openCursor(this.tx, this.cursorConfig);<a name="line.131"></a>
<span class="sourceLineNo">132</span>        } catch (DatabaseException e) {<a name="line.132"></a>
<span class="sourceLineNo">133</span>            throw this.wrapException(e);<a name="line.133"></a>
<span class="sourceLineNo">134</span>        }<a name="line.134"></a>
<span class="sourceLineNo">135</span>        return new CursorIterator(cursor, minKey, maxKey, reverse);<a name="line.135"></a>
<span class="sourceLineNo">136</span>    }<a name="line.136"></a>
<span class="sourceLineNo">137</span><a name="line.137"></a>
<span class="sourceLineNo">138</span>    @Override<a name="line.138"></a>
<span class="sourceLineNo">139</span>    public synchronized void put(byte[] key, byte[] value) {<a name="line.139"></a>
<span class="sourceLineNo">140</span>        if (this.closed)<a name="line.140"></a>
<span class="sourceLineNo">141</span>            throw new StaleTransactionException(this);<a name="line.141"></a>
<span class="sourceLineNo">142</span>        this.cursorTracker.poll();<a name="line.142"></a>
<span class="sourceLineNo">143</span>        if (key.length &gt; 0 &amp;&amp; key[0] == (byte)0xff)<a name="line.143"></a>
<span class="sourceLineNo">144</span>            throw new IllegalArgumentException("key starts with 0xff");<a name="line.144"></a>
<span class="sourceLineNo">145</span>        try {<a name="line.145"></a>
<span class="sourceLineNo">146</span>            this.store.getDatabase().put(this.tx, new DatabaseEntry(key), new DatabaseEntry(value));<a name="line.146"></a>
<span class="sourceLineNo">147</span>        } catch (DatabaseException e) {<a name="line.147"></a>
<span class="sourceLineNo">148</span>            throw this.wrapException(e);<a name="line.148"></a>
<span class="sourceLineNo">149</span>        }<a name="line.149"></a>
<span class="sourceLineNo">150</span>    }<a name="line.150"></a>
<span class="sourceLineNo">151</span><a name="line.151"></a>
<span class="sourceLineNo">152</span>    @Override<a name="line.152"></a>
<span class="sourceLineNo">153</span>    public synchronized void remove(byte[] key) {<a name="line.153"></a>
<span class="sourceLineNo">154</span>        if (this.closed)<a name="line.154"></a>
<span class="sourceLineNo">155</span>            throw new StaleTransactionException(this);<a name="line.155"></a>
<span class="sourceLineNo">156</span>        this.cursorTracker.poll();<a name="line.156"></a>
<span class="sourceLineNo">157</span>        if (key.length &gt; 0 &amp;&amp; key[0] == (byte)0xff)<a name="line.157"></a>
<span class="sourceLineNo">158</span>            throw new IllegalArgumentException("key starts with 0xff");<a name="line.158"></a>
<span class="sourceLineNo">159</span>        try {<a name="line.159"></a>
<span class="sourceLineNo">160</span>            this.store.getDatabase().delete(this.tx, new DatabaseEntry(key));<a name="line.160"></a>
<span class="sourceLineNo">161</span>        } catch (DatabaseException e) {<a name="line.161"></a>
<span class="sourceLineNo">162</span>            throw this.wrapException(e);<a name="line.162"></a>
<span class="sourceLineNo">163</span>        }<a name="line.163"></a>
<span class="sourceLineNo">164</span>    }<a name="line.164"></a>
<span class="sourceLineNo">165</span><a name="line.165"></a>
<span class="sourceLineNo">166</span>    @Override<a name="line.166"></a>
<span class="sourceLineNo">167</span>    public void removeRange(byte[] minKey, byte[] maxKey) {<a name="line.167"></a>
<span class="sourceLineNo">168</span>        try (CursorIterator i = this.getRange(minKey, maxKey, false)) {<a name="line.168"></a>
<span class="sourceLineNo">169</span>            while (i.hasNext()) {<a name="line.169"></a>
<span class="sourceLineNo">170</span>                i.next();<a name="line.170"></a>
<span class="sourceLineNo">171</span>                i.remove();<a name="line.171"></a>
<span class="sourceLineNo">172</span>            }<a name="line.172"></a>
<span class="sourceLineNo">173</span>        }<a name="line.173"></a>
<span class="sourceLineNo">174</span>    }<a name="line.174"></a>
<span class="sourceLineNo">175</span><a name="line.175"></a>
<span class="sourceLineNo">176</span>    @Override<a name="line.176"></a>
<span class="sourceLineNo">177</span>    public synchronized void commit() {<a name="line.177"></a>
<span class="sourceLineNo">178</span>        if (this.closed)<a name="line.178"></a>
<span class="sourceLineNo">179</span>            throw new StaleTransactionException(this);<a name="line.179"></a>
<span class="sourceLineNo">180</span>        this.close();<a name="line.180"></a>
<span class="sourceLineNo">181</span>        try {<a name="line.181"></a>
<span class="sourceLineNo">182</span>            this.tx.commit();<a name="line.182"></a>
<span class="sourceLineNo">183</span>        } catch (DatabaseException e) {<a name="line.183"></a>
<span class="sourceLineNo">184</span>            throw this.wrapException(e);<a name="line.184"></a>
<span class="sourceLineNo">185</span>        }<a name="line.185"></a>
<span class="sourceLineNo">186</span>    }<a name="line.186"></a>
<span class="sourceLineNo">187</span><a name="line.187"></a>
<span class="sourceLineNo">188</span>    @Override<a name="line.188"></a>
<span class="sourceLineNo">189</span>    public synchronized void rollback() {<a name="line.189"></a>
<span class="sourceLineNo">190</span>        if (this.closed)<a name="line.190"></a>
<span class="sourceLineNo">191</span>            return;<a name="line.191"></a>
<span class="sourceLineNo">192</span>        this.close();<a name="line.192"></a>
<span class="sourceLineNo">193</span>        try {<a name="line.193"></a>
<span class="sourceLineNo">194</span>            this.tx.abort();<a name="line.194"></a>
<span class="sourceLineNo">195</span>        } catch (DatabaseException e) {<a name="line.195"></a>
<span class="sourceLineNo">196</span>            throw this.wrapException(e);<a name="line.196"></a>
<span class="sourceLineNo">197</span>        }<a name="line.197"></a>
<span class="sourceLineNo">198</span>    }<a name="line.198"></a>
<span class="sourceLineNo">199</span><a name="line.199"></a>
<span class="sourceLineNo">200</span>// Closeable<a name="line.200"></a>
<span class="sourceLineNo">201</span><a name="line.201"></a>
<span class="sourceLineNo">202</span>    @Override<a name="line.202"></a>
<span class="sourceLineNo">203</span>    public synchronized void close() {<a name="line.203"></a>
<span class="sourceLineNo">204</span><a name="line.204"></a>
<span class="sourceLineNo">205</span>        // Already closed?<a name="line.205"></a>
<span class="sourceLineNo">206</span>        if (this.closed)<a name="line.206"></a>
<span class="sourceLineNo">207</span>            return;<a name="line.207"></a>
<span class="sourceLineNo">208</span>        this.closed = true;<a name="line.208"></a>
<span class="sourceLineNo">209</span><a name="line.209"></a>
<span class="sourceLineNo">210</span>        // Close all unclosed cursors<a name="line.210"></a>
<span class="sourceLineNo">211</span>        this.cursorTracker.close();<a name="line.211"></a>
<span class="sourceLineNo">212</span><a name="line.212"></a>
<span class="sourceLineNo">213</span>        // Remove this transction from database<a name="line.213"></a>
<span class="sourceLineNo">214</span>        this.store.removeTransaction(this);<a name="line.214"></a>
<span class="sourceLineNo">215</span>    }<a name="line.215"></a>
<span class="sourceLineNo">216</span><a name="line.216"></a>
<span class="sourceLineNo">217</span>// Object<a name="line.217"></a>
<span class="sourceLineNo">218</span><a name="line.218"></a>
<span class="sourceLineNo">219</span>    @Override<a name="line.219"></a>
<span class="sourceLineNo">220</span>    protected void finalize() throws Throwable {<a name="line.220"></a>
<span class="sourceLineNo">221</span>        try {<a name="line.221"></a>
<span class="sourceLineNo">222</span>            if (!this.closed)<a name="line.222"></a>
<span class="sourceLineNo">223</span>               this.log.warn(this + " leaked without commit() or rollback()");<a name="line.223"></a>
<span class="sourceLineNo">224</span>            this.close();<a name="line.224"></a>
<span class="sourceLineNo">225</span>        } finally {<a name="line.225"></a>
<span class="sourceLineNo">226</span>            super.finalize();<a name="line.226"></a>
<span class="sourceLineNo">227</span>        }<a name="line.227"></a>
<span class="sourceLineNo">228</span>    }<a name="line.228"></a>
<span class="sourceLineNo">229</span><a name="line.229"></a>
<span class="sourceLineNo">230</span>// Other methods<a name="line.230"></a>
<span class="sourceLineNo">231</span><a name="line.231"></a>
<span class="sourceLineNo">232</span>    /**<a name="line.232"></a>
<span class="sourceLineNo">233</span>     * Wrap the given {@link DatabaseException} in the appropriate {@link KVTransactionException}.<a name="line.233"></a>
<span class="sourceLineNo">234</span>     *<a name="line.234"></a>
<span class="sourceLineNo">235</span>     * @param e Berkeley database exception<a name="line.235"></a>
<span class="sourceLineNo">236</span>     * @return appropriate {@link KVTransactionException} with chained exception {@code e}<a name="line.236"></a>
<span class="sourceLineNo">237</span>     * @throws NullPointerException if {@code e} is null<a name="line.237"></a>
<span class="sourceLineNo">238</span>     */<a name="line.238"></a>
<span class="sourceLineNo">239</span>    public KVTransactionException wrapException(DatabaseException e) {<a name="line.239"></a>
<span class="sourceLineNo">240</span>        if (e instanceof LockConflictException)<a name="line.240"></a>
<span class="sourceLineNo">241</span>            return new RetryTransactionException(this, e);<a name="line.241"></a>
<span class="sourceLineNo">242</span>        return new KVTransactionException(this, e);<a name="line.242"></a>
<span class="sourceLineNo">243</span>    }<a name="line.243"></a>
<span class="sourceLineNo">244</span><a name="line.244"></a>
<span class="sourceLineNo">245</span>    private KVTransactionException weirdStatus(OperationStatus status, String methodName) {<a name="line.245"></a>
<span class="sourceLineNo">246</span>        return new KVTransactionException(BerkeleyKVTransaction.this, "unexpected status " + status + " from " + methodName + "()");<a name="line.246"></a>
<span class="sourceLineNo">247</span>    }<a name="line.247"></a>
<span class="sourceLineNo">248</span><a name="line.248"></a>
<span class="sourceLineNo">249</span>// CursorIterator<a name="line.249"></a>
<span class="sourceLineNo">250</span><a name="line.250"></a>
<span class="sourceLineNo">251</span>    /**<a name="line.251"></a>
<span class="sourceLineNo">252</span>     * {@link Iterator} implementation used by {@link BerkeleyKVTransaction#getRange BerkeleyKVTransaction.getRange()}.<a name="line.252"></a>
<span class="sourceLineNo">253</span>     *<a name="line.253"></a>
<span class="sourceLineNo">254</span>     * &lt;p&gt;<a name="line.254"></a>
<span class="sourceLineNo">255</span>     * Instances implement {@link Closeable}.<a name="line.255"></a>
<span class="sourceLineNo">256</span>     * &lt;/p&gt;<a name="line.256"></a>
<span class="sourceLineNo">257</span>     */<a name="line.257"></a>
<span class="sourceLineNo">258</span>    public final class CursorIterator implements Iterator&lt;KVPair&gt;, Closeable {<a name="line.258"></a>
<span class="sourceLineNo">259</span><a name="line.259"></a>
<span class="sourceLineNo">260</span>        private final Cursor cursor;<a name="line.260"></a>
<span class="sourceLineNo">261</span>        private final byte[] minKey;<a name="line.261"></a>
<span class="sourceLineNo">262</span>        private final byte[] maxKey;<a name="line.262"></a>
<span class="sourceLineNo">263</span>        private final boolean reverse;<a name="line.263"></a>
<span class="sourceLineNo">264</span><a name="line.264"></a>
<span class="sourceLineNo">265</span>        private KVPair nextPair;<a name="line.265"></a>
<span class="sourceLineNo">266</span>        private byte[] removeKey;<a name="line.266"></a>
<span class="sourceLineNo">267</span>        private boolean canRemoveWithCursor;<a name="line.267"></a>
<span class="sourceLineNo">268</span>        private boolean completed;<a name="line.268"></a>
<span class="sourceLineNo">269</span>        private boolean initialized;<a name="line.269"></a>
<span class="sourceLineNo">270</span><a name="line.270"></a>
<span class="sourceLineNo">271</span>        CursorIterator(Cursor cursor, byte[] minKey, byte[] maxKey, boolean reverse) {<a name="line.271"></a>
<span class="sourceLineNo">272</span>            assert Thread.holdsLock(BerkeleyKVTransaction.this);<a name="line.272"></a>
<span class="sourceLineNo">273</span>            assert cursor != null;<a name="line.273"></a>
<span class="sourceLineNo">274</span>            if (minKey != null &amp;&amp; maxKey != null &amp;&amp; ByteUtil.compare(minKey, maxKey) &gt; 0)<a name="line.274"></a>
<span class="sourceLineNo">275</span>                throw new IllegalArgumentException("minKey &gt; maxKey");<a name="line.275"></a>
<span class="sourceLineNo">276</span>            this.cursor = cursor;<a name="line.276"></a>
<span class="sourceLineNo">277</span>            this.minKey = minKey != null ? ByteUtil.min(minKey, BerkeleyKVTransaction.MAX_KEY) : BerkeleyKVTransaction.MIN_KEY;<a name="line.277"></a>
<span class="sourceLineNo">278</span>            this.maxKey = maxKey != null ? ByteUtil.min(maxKey, BerkeleyKVTransaction.MAX_KEY) : BerkeleyKVTransaction.MAX_KEY;<a name="line.278"></a>
<span class="sourceLineNo">279</span>            this.reverse = reverse;<a name="line.279"></a>
<span class="sourceLineNo">280</span><a name="line.280"></a>
<span class="sourceLineNo">281</span>            // Make sure we eventually close the BDB cursor<a name="line.281"></a>
<span class="sourceLineNo">282</span>            BerkeleyKVTransaction.this.cursorTracker.add(this, this.cursor);<a name="line.282"></a>
<span class="sourceLineNo">283</span>        }<a name="line.283"></a>
<span class="sourceLineNo">284</span><a name="line.284"></a>
<span class="sourceLineNo">285</span>    // Iterator<a name="line.285"></a>
<span class="sourceLineNo">286</span><a name="line.286"></a>
<span class="sourceLineNo">287</span>        @Override<a name="line.287"></a>
<span class="sourceLineNo">288</span>        public synchronized boolean hasNext() {<a name="line.288"></a>
<span class="sourceLineNo">289</span>            return this.findNext();<a name="line.289"></a>
<span class="sourceLineNo">290</span>        }<a name="line.290"></a>
<span class="sourceLineNo">291</span><a name="line.291"></a>
<span class="sourceLineNo">292</span>        @Override<a name="line.292"></a>
<span class="sourceLineNo">293</span>        public synchronized KVPair next() {<a name="line.293"></a>
<span class="sourceLineNo">294</span>            if (!this.findNext())<a name="line.294"></a>
<span class="sourceLineNo">295</span>                throw new NoSuchElementException();<a name="line.295"></a>
<span class="sourceLineNo">296</span>            assert this.nextPair != null;<a name="line.296"></a>
<span class="sourceLineNo">297</span>            final KVPair result = this.nextPair;<a name="line.297"></a>
<span class="sourceLineNo">298</span>            this.removeKey = result.getKey().clone();<a name="line.298"></a>
<span class="sourceLineNo">299</span>            this.canRemoveWithCursor = true;<a name="line.299"></a>
<span class="sourceLineNo">300</span>            this.nextPair = null;<a name="line.300"></a>
<span class="sourceLineNo">301</span>            return result;<a name="line.301"></a>
<span class="sourceLineNo">302</span>        }<a name="line.302"></a>
<span class="sourceLineNo">303</span><a name="line.303"></a>
<span class="sourceLineNo">304</span>        @Override<a name="line.304"></a>
<span class="sourceLineNo">305</span>        public synchronized void remove() {<a name="line.305"></a>
<span class="sourceLineNo">306</span>            if (BerkeleyKVTransaction.this.closed)<a name="line.306"></a>
<span class="sourceLineNo">307</span>                throw new StaleTransactionException(BerkeleyKVTransaction.this);<a name="line.307"></a>
<span class="sourceLineNo">308</span>            if (this.removeKey == null)<a name="line.308"></a>
<span class="sourceLineNo">309</span>                throw new IllegalStateException();<a name="line.309"></a>
<span class="sourceLineNo">310</span>            try {<a name="line.310"></a>
<span class="sourceLineNo">311</span>                final OperationStatus status = this.canRemoveWithCursor ? this.cursor.delete() :<a name="line.311"></a>
<span class="sourceLineNo">312</span>                  this.cursor.getDatabase().delete(BerkeleyKVTransaction.this.tx, new DatabaseEntry(this.removeKey));<a name="line.312"></a>
<span class="sourceLineNo">313</span>                switch (status) {<a name="line.313"></a>
<span class="sourceLineNo">314</span>                case SUCCESS:<a name="line.314"></a>
<span class="sourceLineNo">315</span>                case KEYEMPTY:<a name="line.315"></a>
<span class="sourceLineNo">316</span>                    break;<a name="line.316"></a>
<span class="sourceLineNo">317</span>                default:<a name="line.317"></a>
<span class="sourceLineNo">318</span>                    throw BerkeleyKVTransaction.this.weirdStatus(status, "delete");<a name="line.318"></a>
<span class="sourceLineNo">319</span>                }<a name="line.319"></a>
<span class="sourceLineNo">320</span>            } catch (DatabaseException e) {<a name="line.320"></a>
<span class="sourceLineNo">321</span>                throw BerkeleyKVTransaction.this.wrapException(e);<a name="line.321"></a>
<span class="sourceLineNo">322</span>            }<a name="line.322"></a>
<span class="sourceLineNo">323</span>            this.removeKey = null;<a name="line.323"></a>
<span class="sourceLineNo">324</span>        }<a name="line.324"></a>
<span class="sourceLineNo">325</span><a name="line.325"></a>
<span class="sourceLineNo">326</span>    // Closeable<a name="line.326"></a>
<span class="sourceLineNo">327</span><a name="line.327"></a>
<span class="sourceLineNo">328</span>        @Override<a name="line.328"></a>
<span class="sourceLineNo">329</span>        public void close() {<a name="line.329"></a>
<span class="sourceLineNo">330</span>            try {<a name="line.330"></a>
<span class="sourceLineNo">331</span>                this.cursor.close();<a name="line.331"></a>
<span class="sourceLineNo">332</span>            } catch (Throwable e) {<a name="line.332"></a>
<span class="sourceLineNo">333</span>                BerkeleyKVTransaction.this.log.debug("caught exception closing iterator cursor (ignoring)", e);<a name="line.333"></a>
<span class="sourceLineNo">334</span>            }<a name="line.334"></a>
<span class="sourceLineNo">335</span>        }<a name="line.335"></a>
<span class="sourceLineNo">336</span><a name="line.336"></a>
<span class="sourceLineNo">337</span>    // Internal methods<a name="line.337"></a>
<span class="sourceLineNo">338</span><a name="line.338"></a>
<span class="sourceLineNo">339</span>        @SuppressWarnings("fallthrough")<a name="line.339"></a>
<span class="sourceLineNo">340</span>        private /*synchronized*/ boolean findNext() {<a name="line.340"></a>
<span class="sourceLineNo">341</span>            assert Thread.holdsLock(this);<a name="line.341"></a>
<span class="sourceLineNo">342</span>            if (BerkeleyKVTransaction.this.closed)<a name="line.342"></a>
<span class="sourceLineNo">343</span>                throw new StaleTransactionException(BerkeleyKVTransaction.this);<a name="line.343"></a>
<span class="sourceLineNo">344</span>            if (!this.initialized)<a name="line.344"></a>
<span class="sourceLineNo">345</span>                this.initialize();<a name="line.345"></a>
<span class="sourceLineNo">346</span>            assert this.initialized;<a name="line.346"></a>
<span class="sourceLineNo">347</span>            if (this.nextPair != null)<a name="line.347"></a>
<span class="sourceLineNo">348</span>                return true;<a name="line.348"></a>
<span class="sourceLineNo">349</span>            if (this.completed)<a name="line.349"></a>
<span class="sourceLineNo">350</span>                return false;<a name="line.350"></a>
<span class="sourceLineNo">351</span>            final DatabaseEntry key = new DatabaseEntry();<a name="line.351"></a>
<span class="sourceLineNo">352</span>            final DatabaseEntry value = new DatabaseEntry();<a name="line.352"></a>
<span class="sourceLineNo">353</span>            this.canRemoveWithCursor = false;<a name="line.353"></a>
<span class="sourceLineNo">354</span>            try {<a name="line.354"></a>
<span class="sourceLineNo">355</span>                final OperationStatus status = this.reverse ?<a name="line.355"></a>
<span class="sourceLineNo">356</span>                  this.cursor.getPrev(key, value, null) : this.cursor.getNext(key, value, null);<a name="line.356"></a>
<span class="sourceLineNo">357</span>                switch (status) {<a name="line.357"></a>
<span class="sourceLineNo">358</span>                case SUCCESS:<a name="line.358"></a>
<span class="sourceLineNo">359</span>                    final byte[] keyData = key.getData();<a name="line.359"></a>
<span class="sourceLineNo">360</span>                    if (this.reverse ? ByteUtil.compare(keyData, this.minKey) &gt;= 0 : ByteUtil.compare(keyData, this.maxKey) &lt; 0) {<a name="line.360"></a>
<span class="sourceLineNo">361</span>                        this.nextPair = new KVPair(keyData, value.getData());<a name="line.361"></a>
<span class="sourceLineNo">362</span>                        return true;<a name="line.362"></a>
<span class="sourceLineNo">363</span>                    }<a name="line.363"></a>
<span class="sourceLineNo">364</span>                    // FALLTHROUGH<a name="line.364"></a>
<span class="sourceLineNo">365</span>                case NOTFOUND:<a name="line.365"></a>
<span class="sourceLineNo">366</span>                    this.completed = true;<a name="line.366"></a>
<span class="sourceLineNo">367</span>                    return false;<a name="line.367"></a>
<span class="sourceLineNo">368</span>                default:<a name="line.368"></a>
<span class="sourceLineNo">369</span>                    throw BerkeleyKVTransaction.this.weirdStatus(status, this.reverse ? "getPrev" : "getNext");<a name="line.369"></a>
<span class="sourceLineNo">370</span>                }<a name="line.370"></a>
<span class="sourceLineNo">371</span>            } catch (DatabaseException e) {<a name="line.371"></a>
<span class="sourceLineNo">372</span>                throw BerkeleyKVTransaction.this.wrapException(e);<a name="line.372"></a>
<span class="sourceLineNo">373</span>            }<a name="line.373"></a>
<span class="sourceLineNo">374</span>        }<a name="line.374"></a>
<span class="sourceLineNo">375</span><a name="line.375"></a>
<span class="sourceLineNo">376</span>        // We initialize on demand from findNext()<a name="line.376"></a>
<span class="sourceLineNo">377</span>        @SuppressWarnings("fallthrough")<a name="line.377"></a>
<span class="sourceLineNo">378</span>        private /*synchronized*/ void initialize() {<a name="line.378"></a>
<span class="sourceLineNo">379</span>            assert Thread.holdsLock(this);<a name="line.379"></a>
<span class="sourceLineNo">380</span>            assert !this.initialized;<a name="line.380"></a>
<span class="sourceLineNo">381</span>            assert !this.completed;<a name="line.381"></a>
<span class="sourceLineNo">382</span>            assert this.nextPair == null;<a name="line.382"></a>
<span class="sourceLineNo">383</span>            if (reverse) {<a name="line.383"></a>
<span class="sourceLineNo">384</span><a name="line.384"></a>
<span class="sourceLineNo">385</span>                // Search for maxKey; thereafter, a call to getPrev() will return the first element in the reverse iteration.<a name="line.385"></a>
<span class="sourceLineNo">386</span>                // We don't care whether maxKey is found or not, we are just positioning the cursor.<a name="line.386"></a>
<span class="sourceLineNo">387</span>                try {<a name="line.387"></a>
<span class="sourceLineNo">388</span>                    final OperationStatus status = this.cursor.getSearchKey(<a name="line.388"></a>
<span class="sourceLineNo">389</span>                      new DatabaseEntry(this.maxKey), new DatabaseEntry(), null);<a name="line.389"></a>
<span class="sourceLineNo">390</span>                    switch (status) {<a name="line.390"></a>
<span class="sourceLineNo">391</span>                    case SUCCESS:<a name="line.391"></a>
<span class="sourceLineNo">392</span>                    case NOTFOUND:<a name="line.392"></a>
<span class="sourceLineNo">393</span>                        break;<a name="line.393"></a>
<span class="sourceLineNo">394</span>                    default:<a name="line.394"></a>
<span class="sourceLineNo">395</span>                        throw BerkeleyKVTransaction.this.weirdStatus(status, "getSearchKey");<a name="line.395"></a>
<span class="sourceLineNo">396</span>                    }<a name="line.396"></a>
<span class="sourceLineNo">397</span>                } catch (DatabaseException e) {<a name="line.397"></a>
<span class="sourceLineNo">398</span>                    throw BerkeleyKVTransaction.this.wrapException(e);<a name="line.398"></a>
<span class="sourceLineNo">399</span>                }<a name="line.399"></a>
<span class="sourceLineNo">400</span>            } else if (this.minKey.length &gt; 0) {    // if minKey has zero length, no need to initialize (getNext() will just work)<a name="line.400"></a>
<span class="sourceLineNo">401</span>                final DatabaseEntry key = new DatabaseEntry(this.minKey);<a name="line.401"></a>
<span class="sourceLineNo">402</span>                final DatabaseEntry value = new DatabaseEntry();<a name="line.402"></a>
<span class="sourceLineNo">403</span>                try {<a name="line.403"></a>
<span class="sourceLineNo">404</span>                    final OperationStatus status = this.cursor.getSearchKeyRange(key, value, null);<a name="line.404"></a>
<span class="sourceLineNo">405</span>                    switch (status) {<a name="line.405"></a>
<span class="sourceLineNo">406</span>                    case SUCCESS:<a name="line.406"></a>
<span class="sourceLineNo">407</span>                        final byte[] keyData = key.getData();<a name="line.407"></a>
<span class="sourceLineNo">408</span>                        if (ByteUtil.compare(keyData, this.maxKey) &lt; 0) {<a name="line.408"></a>
<span class="sourceLineNo">409</span>                            this.nextPair = new KVPair(keyData, value.getData());<a name="line.409"></a>
<span class="sourceLineNo">410</span>                            break;<a name="line.410"></a>
<span class="sourceLineNo">411</span>                        }<a name="line.411"></a>
<span class="sourceLineNo">412</span>                        // FALLTHROUGH<a name="line.412"></a>
<span class="sourceLineNo">413</span>                    case NOTFOUND:<a name="line.413"></a>
<span class="sourceLineNo">414</span>                        this.completed = true;<a name="line.414"></a>
<span class="sourceLineNo">415</span>                        break;<a name="line.415"></a>
<span class="sourceLineNo">416</span>                    default:<a name="line.416"></a>
<span class="sourceLineNo">417</span>                        throw BerkeleyKVTransaction.this.weirdStatus(status, "getSearchKeyRange");<a name="line.417"></a>
<span class="sourceLineNo">418</span>                    }<a name="line.418"></a>
<span class="sourceLineNo">419</span>                } catch (DatabaseException e) {<a name="line.419"></a>
<span class="sourceLineNo">420</span>                    throw BerkeleyKVTransaction.this.wrapException(e);<a name="line.420"></a>
<span class="sourceLineNo">421</span>                }<a name="line.421"></a>
<span class="sourceLineNo">422</span>            }<a name="line.422"></a>
<span class="sourceLineNo">423</span>            this.initialized = true;<a name="line.423"></a>
<span class="sourceLineNo">424</span>        }<a name="line.424"></a>
<span class="sourceLineNo">425</span>    }<a name="line.425"></a>
<span class="sourceLineNo">426</span>}<a name="line.426"></a>
<span class="sourceLineNo">427</span><a name="line.427"></a>




























































</pre>
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